Steel Bearing Plate between a Round Column and Beam

[Buleeek]

Hi everyone,

Recently, I have been trying to check if a bearing plate is necessary between a round column (HSS Round 3"x.25") and a W beam (W8x28). I found a procedure, but I can't find a definite answer what to do when a bearing plate is not fully supported (bears on a round hollow column). I think the beam flange still works as a cantilever, but the load on it is not uniform, like when beam rest on concrete wall. Can someone help me with that? Maybe someone has a procedure ready and could share it with me? Thanks for all the input!

 

[dhengr]

Buleeek:
Is that a bearing plate or a column cap pl? Remember, stl. to stl. bearing is a lot higher than stl. to conc. bearing. Use a fairly thick cap pl. to widen the bearing length/area, and check the beam web crippling where it crosses the column wall. That is basically where the beam will be bearing, on the col. wall thk., plus some weld area, over some length. What about cap pl. size for bolts?

Edit: The bearing stress under the beam, on a conc. wall is not uniform, even though we kinda assume it is. History/experience shows this works and simplifies our calcs. The beam flgs. do act like cantilevers to distribute the load, but still-in-all, the majority of the bearing load is within a couple inches either side of the beam web, k width and all, the stiffest area of the beam bearing. Then, the bearing stress peters out fairly quickly as a function of the flg. stiffness acting as that canti. out to the flg. tip.

 

[jdonville]

From the description, it sounds like the W-beam is bearing on the "circle" of the column, but with the web of the beam not centered on the circle.

For peace of mind, I would have a round or square cap stitch-welded on the round HSS and maybe a stiffener on the side of the W-beam closest to the center of the circular section.

I would still be concerned about the eccentricity of the load on the column, any moment introduced into the column, and the connection details of the beam to the cap.